Food Technology Food Microbiology Preservation of Foods by Physical Methods

Paper No. : 03 Food Microbiology Module : 11 Preservation of foods by physical methods – Radiation

Development Team

Principal Investigator Prof. (Mrs.) Vijaya Khader, Ph.D Former Dean, Acharya N G Ranga Agricultural University

Paper Coordinator Professor A. K. Puniya National Dairy Research Institute (NDRI), Karnal

Food Microbiology Food Technology Preservation of foods by physical methods – Radiation

Description of Module Content Writer Dr. Tejpal Dhewa Bhaskarcharya College of Applied Sciences (University of Delhi) Subject Name Food Technology

Paper Name 03 Food Microbiology

Module Name/Title Preservation of foods by physical methods – Radiation

Module Id FT/FM/11

Pre-requisites Behavior and types of radiations, effect of radiations on microbial system

Objectives To study about types and food applications of radiations for preservation of various types of foods. Keywords Irradiations, UV, Gamma radiations

Prof. (Mrs.) Vijaya Khader, Ph.D Content Reviewer Former Dean, Acharya N G Ranga Agricultural University Dr. MC Varadaraj , Chief Scientist CSIR-CFTRI, Mysore

Food Microbiology Food Technology Preservation of foods by physical methods – Radiation

Glossary

Starting Term Definition Related Term Character C Curie It is a quantity of radioactive substance in which 3.7 x 1010 radioactive disintegrations occur per second. Becquerel (Bq): It is a new unit for a curie.

D Dose irradiation The dose of irradiation is the amount of energy absorbed by the food quantity of mass. Gray or Gy (SI

Unit) is a unit of dose of radiation; 1 Gy = one joule per kilogram of food; 1 rad = 10-2Gy.

Dose rate Determined by the dose absorbed by the food, per unit of exposure time. Unit is: kilowatts/kilogram of food or

kGy per unit time.

M milliroentgen Equivalent to 1/1000 of a roentgen.

R Rad A rad is a unit equal to the absorption of 100 ergs/g of matter.

Radappertisation In which 20 to 50 kGy dose of radiation is used to Radiosterilization destroy all microorganisms.

Radicisation Dose of radiation is 10 kGy or less to destroy all non- Radiopasteurization

Food Microbiology Food Technology Preservation of foods by physical methods – Radiation

sporulating/ vegetative forms of pathogens.

Radurisation This process is used to reduce the microbial load without affecting the quality of product by using the dose of radiation 5 kGy or less.

Roentgen Unit of radiation measure.

Did you know???

Description Image Source

Food irradiated by exposing it to the gamma rays of http://www.chem.duke.e a radioisotope: one that is widely used is cobalt-60. du/~jds/cruise_chem/nuc The energy obtained from the gamma ray passing lear/pics/fruit.gif through the food is enough to destroy many

pathogenic and spoilage causing bacteria.

As the food never comes in contact with the radioisotope. Hence, no risk of becoming

radioactive.

Difference between irradiation and pasteurization: http://upload.wikimedia. Irradiation uses high doses of radiation to eliminate org/wikipedia/commons/ or inactivate bacteria and viruses. Irradiation kills 8/8b/ISSSpaceFoodsAss all of the pathogens in the targeted food, whereas ortment.jpg pasteurization does not. Products that have been irradiated have a much longer shelf life, when compared to pasteurized products. Due to the

similar results of the two processes, irradiation is sometimes referred to as “cold pasteurization.”

Food Microbiology Food Technology Preservation of foods by physical methods – Radiation

The Killer Paper: Scientists at Israel’s Bar-Ilan http://www.thehindu.co University have revealed the "killer paper", a new m/multimedia/dynamic/0 packaging material made of anti-bacterial 0484/07399e1f_484054f. nanoparticles (paper contains a coating of silver jpg nanoparticles which are powerful anti-bacterial

agents). Such material could provide an alternative to common food preservation methods such as radiation.

Web links and references

a. Link to Wikipedia, Blogs, Link to Similar Topic Web links

http://www.iaea.org/Publications/Magazines/Bulletin/Bull233/23305783336.pdf

http://www.epa.gov/radiation/sources/food_history.html

http://nsdl.niscair.res.in/bitstream/123456789/305/2/FoodPreservation.pdf

http://en.wikipedia.org/wiki/Food_irradiation

http://en.wikipedia.org/wiki/Food_preservation

http://www.epa.gov/radiation/sources/food_irrad.html

http://foodadditive.blogspot.in/2008/04/food-radiation.html

Food Microbiology Food Technology Preservation of foods by physical methods – Radiation

b. References  Adams M.R. and Moss M.O. Food Microbiology, 4th edition, New Age International (P) Limited Publishers, New Delhi, India, 1995.  Banwart J.M. Basic Food Microbiology, 1stedition. CBS Publishers and Distributors, Delhi, India, 1987.  Frazier W.C. and Westhoff D.C. Food Microbiology, 3rd edition. Tata McGraw-Hill Publishing Company Ltd, New Delhi, India, 1992.  Jay J.M., Loessner M.J. and Golden D.A. Modern food microbiology, 7th edition, CBS Publishers and Distributors, Delhi, India, 2005.

Food Microbiology Food Technology Preservation of foods by physical methods – Radiation